This invention provides an orthodontic rotation spring for rotating a selected tooth about its axis.
It is a common technique of orthodontia to anchor an arch wire to two or more teeth in the mouth, and stress the arch wire at one or more points in order to effect a realignment of preselected teeth. A separate tooth band is typically cemented around each of several teeth, orthodontic brackets having been welded to each respective tooth band. An arch wire is fastened to and interconnects the orthodontic brackets.
One way of applying the required stress to a given tooth is to supply a spring which is anchored to the orthodontic bracket, and bears against the tooth (and typically against the arch wire as well). Many prior art spring devices have the problem that there is a terminating surface in proximity to the wearer's cheek or lip. This can cause irritation and discomfort to the wearer.
A further difficulty encountered with many prior art rotation springs is the lack of positive positioning. Thus, the spring is subject to movement perpendicular to the arch wire, which movement may unduly stress the spring mounting at the orthodontic bracket.
Yet another difficulty with many prior art springs is that they are relatively expensive to manufacture, as for example if they incorporate multiple parts that must be welded together. This can also result in additional points for potential failure.
Accordingly, there is a need for an orthodontic rotation spring which terminates away from the wearer's cheek or lip, is not subject to motion perpendicular to the arch wire, and which is simple to manufacture.